Fluid operated motor with piston actuated distributing valve and manually actuated parking valve



Oct; 5 1948. v c R SAC |N| $450,564

FLUID OPERATED MOTOR WITH PIS o ACTUA'IED DISTRIBUTING VALVE ANDMANUALLY ACTUATED PARKING VALVE Filed Oct. 2, 1944 5 Sheets-Sheet l//vI/E/v7"0 /z C'0 wmus fine I ////v/ (47-7-0 rr/vz v Oct. 5, 1948. c, scc I 2,450,564

FLUID OPERATED MOTOR WITH PISTON ACTUATED DISTRIBUTING VALVE ANDMANUALLY ACTUATED PARKING VALVE Filed 001;. 2, 1944 3 Sheets-Sheet 2Oct. 5, 1948. c, s ccHl 2,450,564

FLUID OPERATED MOTOR WITH PISTON ACTUATED DISTRIBUTING VALVE ANDMANUALLY ACTUATED PARKING VALVE Filed 001;. 2, 1944 3 Sheets-Sheet 3F/Gj x 1 5 v w: 3 ma H7 95 i I 7 I COL UMBUS IfSfic'CH/N/ 5 dww lra/fA/EY' Patented Oct. 5, 1948 FLUID OPERATED MOTOR WITH PISTONACTUATED DISTRIBUTING VALVE AND MANUALLY ACTUATED PARKING VALVE ColumbusR. Sacchini, Willoughby, Ohio, assignor to The Marquette Metal ProductsCompany, Cleveland, Ohio, a corporation of Ohio Application October 2,1944, Serial No. 556,853

9 Claims.

This invention relates to an improved fluid operated motor of the typeadapted to be used for driving a reciprocatable or oscillatable wiperelement, as for Windshields of air and land vehicles. The motor shownherewith is on the order of that disclosed and claimed in my Patent2,404,747 issued July 23, 1946, application for which was co-pendingherewith and the principal practical uses of the present motor as wellas problems connected therewith are generally the same as thosediscussed in said application.

The principal objects hereof are: to provide, a fluid operatedreciprocating piston motor capable of being made in compact form, lightweight and capable of delivering the necessary power for vehicle windowand windshield wiping service at high vehicle speed and under otheradverse conditions; to provide an improved valve and snap actionmechanism for automatically reversing fluid flow in the motor to causecontinued reciprocation of the power piston thereof; to provide animproved parking arrangement for fluid operated window or windshielddriving motors, and to provide an improved arrangement for limiting theinput of fluid, thereby to control the top motor speed.

A specific object is to provide a rotary fluid-reversing valve for areciprocating motor of the type shown, wherein fluid introduced to anddirected by the valve is so applied as to balance side thrust of theturning element of the valve on opposite sides of the turning axis,thereby overcoming to a large extent the tendency for the rotary elementto resist being turned out of stopped position and enabling said elementto be turned from one control position to another by a very small torqueeffort.

A further object is to provide a combined rotary valve and snap actionmechanism in which the rotary element of the valve is dislodged fromeach stopped position by a hammer blow or impact of the snap actionmechanism thereon, whereby to overcome initial static friction.

A further general object is to provide a fluid operated motorincorporating all the necessary operating features to enable it to meetthe various practical requirements of aircraft installations and others.

A further object is to provide a fluid operated motor having an improvedadjustable valving means operable to limit power input to the motor.

Other objects relate to constructional features of the motor as will bebrought out later herein.

In the accompanying drawings:

Fig. l is a rear elevation of a preferred form of fluid operated motorembodying the principles hereof, shown with a-rear closure plate removedto expose a snap action toggle mechanism and associated parts;

Fig. 2 is a vertical sectional view taken generally along the line 2-2on Fig. 1;

Fig. 3 is a vertical sectional view taken general- 1y along the line 33on Fig. 2 further showing the motor and valve construction;

Fig. 4 is a perspective viewof the main or reversing valve cylinder ofthe motor; 7

Fig. 5 is a perspective view of the valve sleeve in which the valvecylinder of Fig. 4 operates;

Fig, 6 is a sectional plan View of the main housing taken in ahorizontal plane generally along the line 6-8 on Figs. 1 and 3principally further to illustrate the inlet and outlet fluid conduits inrelation to the valve bores of the housing;

Fig. 7 is a detail sectional view of the parking valve control, with theadjustable control element turned to parking position, i. e. from theposition in which shown on Fig. 3 and Fig. Sis a plan view of a trunnionpivot element of the snap action toggle mechanism.

The motor operates properly in any turned position, hence terms such asfront, rear, upward, and downward are not to be considered restrictivein any sense.

Referring to Figs. 1 to 3, a tubular member or bushing IE], Fig. 2,operatively rigid with a generally hollow, irregularly shaped bodymember H for the motor is shown as rotatably supporting a power take-offshaft I2 having spline serrations at its outer end portion [4. Thesplined portion [4 is adapted to receive, in adjusted turned positions,a windshield wiper blade drive arm (not shown) or other load drivingmeans having a complementary splined socket. The motor may be mountedrearwardly of a windshield (not shown) in any suitable manner with thetubular member It extending outwardly through the usual windshieldsupporting framework or casing.

As shown most clearly in Fig. 3, spaced apart piston sleeves l5 and Itare pressed respectively into aligned openings in opposing side walls ofthe body H, and have their outer ends extending freely into outercounterbored portions of the openings. The counterbored portions arethreaded to receive respective externally flanged,cylinder-head-constituting plugs 13 and 19 which are cup-shaped todefine inner cylindrical recesses l3 and H. When the plugs l8 and 19 arescrewed into position so that the flanges are in sealing engagement withsuitable gaskets l8 and IS the inner annular face portions of the plugssurrounding the recesses I3 and Il are each spaced a short distance fromthe bottom of the respective counterbore to define annular grooves 2|and 22. The outer end portion of each of the sleeves l5 and It extendsfreely into the respective recess It or I! in spaced relation to thebottom thereof to permit fluid to flow from the grooves 2| and 22 intopiston chambers formed largely by the sleeves l5 and IS.

A central rack portion 25 of a piston 25 interconnects opposing pistonhead portions 25 and 28 which are slidably received within the sleevesl5 and I6, respectively, and which may be provided with suitable annularsealing members 29 and 39, respectively, suitably secured to theassociated piston heads as by screws 29' and 30'. Piston chambers 3! and32 are thus formed within the sleeves i5 and [5 between the outer facesof the head portions 2% and 23 and the plugs ably has formed integrallytherewith a gear sector 34 with teeth 35 maintained in mesh with teethof the rack bar portion 24 of the piston by the tubular support IQ forsaid shaft which support is removable from the housing H in theparticular arrangement shown.

The support it for the shaft 12 is an integral part of a tubular bracketmember 3'6 screw threaded to the casing H as at 3?. The bracket 36 has aflange 38' adjacent the threaded connection whichlatter whenestablished, as by turning the flange with a wrench engaged with radialnotches 39 in the flange, causes the flange to become seated in acounterbore at; in the forward face of the housing H. A necked portionl! of the bracket adjacent the threads receives a ring 42 of elasticcompressible sealing material which ring is expanded and forced over thethreads for contraction against or into the neck 4!. A counterboreportion 45' forwardly from the threaded connection3l' receives thesealing ring. The internal threads of the threaded connection 37terminate adjacent the counterbore portion .6 in'such manner that whenthe bracketis screwed into place the ringis compressed between theforward terminal surfaces of the internal threads and the flange 33making a squeeze seal all. around the bracket.

The rearward end of the bracket is in the form of a tubular flange 44sufficiently smaller than the threaded opening (threaded connection 31)to enable insertion of the bracket into the position shown butnevertheless large enough to contain a sealing unit 45 of adequatecapacity to block egress of operating fluid from the interior of thehousing outwardly along the shaft 12; The sealing unit 45 comprises athreaded ring 46 recessed on its forward side to contain and compress aring of elastic sealing material 41. The sealing unit 55 is madesubstantially according to U. S. Patent 2,376,011 issued May 15, 1945',out of application Serial'No. 463,745, filed October 29, 1942, said unitbeing adjusted to secure the desired degree of compression of the ring41 against the shaft by turning the annular member 46 in its threadedconnection with the bracket. In effecting assembly of the shaft andbracket 36 into the housing the gear sector carrying portion of theshaft is passed through the opening which receives thebracket 35into'the interior of the housing and meshed with the teeth of the rackbar and thereupon the bracket with its sealing unit d5 assembled thereonis slid over the free end of the shaft and then threaded into place at37 as described.

A rotary valve assembly for the motor comprises a valve cylinder Ellrotatably received within a sleeve 5i pressed into a complementary bore52 extending through the front wall of the body ii. The forward end ofthe bore 52 (Fig. 2) is counterbored to receive a closure plate 54 whichmay comprise an initially concave-convex expansion plug or disc of wellknown form or simply a flat disc pressed tightly into the counterbore.By means of this construction, it is a simple matter to accuratelyfinish the inner surface of the sleeve til-after the latter has beenpressed into position and then to close the outer end of the bore 52with the plate 54'. The valve construction will be more fully describedlater.

A snap action toggle mechanism 55 is. provided (in a generallyrectangular'recess 53 in therear portion of the housing ll) between thepiston and the valve cylinder in order to insure thatithe valve cylinderwill, at cessation'of operation; of the mechanism, always occupy one oftwo'relatively reversed positions and not some position between thosetwo; whereby the wiper operated by the motor will stop at one end ofitsstroke and whereby upon resumption of the; supply. of workingpressure the. motor will'be, certain to operate. 7

Thesnap action mechanism 55isof unitary character and constitutes witharear closure plate 56 for the recess 57 of the housing; II, aselfsustaining sub-assembly which canbeibrought into proper operativeassociationwith the piston and valve mechanism by attachment of the.closure plate 55 over the generally rectangularzrecess 51 as by screws53. The closure platemay have a gasket, not shown, interposed between itand the adjacent housing walls surrounding the recess 5?.

Said unitary toggle assembly iscarried on' a trunnion or hollow yokemember 59, seeFigs; 1, 2 and 8, supported against the forward facezofthe closure plate 355. The trunnion. or yoke "memher, as shownparticularly'by Fig. 8, is an open frame with mutuallyrigidthorizontally extending spacedsides 59' which carry axially alignedcylindrical toggle-arm-supporting pivot pins-6t and (ii. The pin 88, asshown, is riveted. as at E2'a'djacent an opening in the closure plateofi'against which a shoulder '63 of the pin' is maintained tightly bythe riveting. The pins Gil-and: 8i constitute a trunnion mounting. for.upper and lower toggle arms 65 and 55,'respectively, eachcomposed of apair of parallel spacedarm membersfi'liessentially alike in constructionbut of different lengths. The members fi'l' of the arm 63 are somewhatlonger than those of the arm 65..

The parallel arm members 67' of the arms-'65 and 56 are held in parallelposition bythe trun- 'nion pins 6d and 5! on which theyare journalled oftheconnecting-pins 58 are rivetedover against "pins on the adjacentoutward faces of the arm members 61 as at 68'. The roller sleeves 69 areperipherally grooved midway between their ends as at 69 for engagementwith looped portions and 14, respectively, of a tension spring 64 whichpasses through the opening provided by the parallel sides 59 of thetrunnion member 59. The spring thus connects the outer ends of the twotoggle arms 65 and 66 and tends to move one toggle arm counterclockwiseand, simultaneously, the other arm clockwise beyond a dead centerposition in which the two toggle arms are in alignment.

The final swung position of the two arms 65 and 66 in one direction ofoperation is illustrated in full lines in Fig. 1, said arms being heldin the position so illustrated by abutment of the arm 65 with an innerwall of the recess 51 at 12. At both extreme movements of the arm 65 thearm members 61 so strike the inner walls of the recess thus guarding theupper spring 1001) from impact. The other arm 66 of the toggle mechanismis maintained in a similarly limited position at each stroke but byoperation of one of a pair of the valve cylinder 50 engaged by the arm66. The arm 65 is operated by the power piston 25 and the arm 66,through such pins, operates the valve cylinder to turn it alternatelyback and forth as will be described below.

The operating mechanism on the piston for engagement with the forwardlydeposed arm members 61 of the arm 65 comprises a plate secured to therear face of the rack portion of the piston as by a single screw 16. Theplate 15 is additionally maintained in position on the piston by reasonof engagement of the side edges of the plate with shoulders 11, see Fig.3 on the piston portion 24. The plate 15 is removed from Fig. 3 but theextent of the plate upwardly from the rack portion of the piston isindicated by broken lines 15m. It may be noted on Fig. 2 that the twoforwardly disposed arm members 61 of the toggle arms 65 and 66 aremaintained in position on the trunnion pin 6! by the riveted overforward ends of the cross pins 68 so that neither arm member 61 rubsagainst the plate 15. The forward end of the trunnion pin 6| alsoslightly clears the plate 15. The trunnion, or duplex pivot support forthe toggle arm assembly prevents cantilever action which might tend tomake the arms bind at their pivots under the force of the tension spring64. The spring acts with equal force on all the arm members 61 asdetermined by its central position of attachment with respect to thecylindrical roller sleeves 69.

For operation of the reversing valve cylinder 56 the plate 15 isprovided with two pins 86 and 81 the relative position of which on theplate is illustrated best diagrammatically on Fig. 3, said pinsprojecting rearwardly from the plate 15 a short distance for engagementwith the forwardly positioned upper arm member 61 as mentioned above.When the piston moves in one direction, as to the right in Fig. 3, thepin 86 thus engages the arm 65 and swings the same from the solid lineposition shown by Fig. 1 and slightly past the dotted line illustratedposition into an opposite position at the other side of the recess 51.At an intermediate portion of the travel of the piston from left toright the spring 64 of the toggle mechanism causes the lower arm 66 tobe swung quickly from the position shown in solid lines in Fig. l to thecorresponding opposite direction shown by broken lines. No movement ofthe arm 66 takes place until the upper arm 65 has. been moved into andslightly past a dead center position in line with the arm 65 orapproximately as shown by dotted lines. Then the snap action occurs. Thevalve cylinder is held against rotary movement by the lower toggle armuntil the snap action occurs as will be described later.

When the arm 66 swings from its full line illustrated position on Fig. lto the broken line illustrated position the arm turns the valve cylinder50 through an angle, for instance, of 60 degrees by virtue of abutmentbetween the forward arm member'61 of the arm 66 and a pin 83 projectingfrom a segment-shaped rearwardly overhanging portion of the valvecylinder positioned, as shown best by Fig. 4, forwardly beyond the valvesleeve 5| but closely adjacent the rearward extremity of the sleeve. Asimilar pin 82 on the portion 85 of the valve cylinder is engaged by thearm 66 during its return movement from the broken line to the solid lineillustrated position. The pins are symmetrically located with respect tothe center of the segmental extension 85 so that the valve is turnedexactly through the same degree in each direction from a central neutralposition of the valve cylinder. The pins 812 and 83 also are so locatedon the extension 85 of the valve cylinder as to arrest the arm 66 of thetoggle mechanism and the valve cylinder when and only when the valvecylinder has been turned through the desired angle. One arrestedposition of the valve cylinder and toggle arm 66 is illustrated byFig. 1. A line drawn through the 'center of the pin 82 and passingthrough the center of the valve cylinder is perpendicular to theadjacent side edge of the arm member 61 of the toggle arm 66 lWhl-Chmakes driving contact with said pin. Therefore, the spring forcecontinues to exert pressure on the pin 82 in the necessary direction toturn the valve cylinder until the above mentioned perpendicular positionof the pin 32 is attained and thereafter the turning force of the springon the valve cylinder becomes zero. Arrested relative position of thetoggle arm and valve cylinder is attained without shock to the parts yetnevertheless the action is positive.

Referring now to the fluid system of the motor an inlet 99 for fluidunder pressure is shown in Fig. 3 at the right hand lower portion of thehousing II and an outlet 9| is similarly formed in the housing at theleft and which may, for convenience and symmetry, be directly oppositethe inlet. The inlet and outlet openings are threaded to receiveappropriate high pressure fluid connections, the threads 92 of the inletalso accommodating a metering orifice plug 93 having a central hole 94of accurately measured diameter so that the volume of fluid that can beintroduced to the motor in a given time is definitely limited. Suchlimiting is always desirable in connection with hydraulic fluid motorswhere the supply pressure may run rather high at times, particularly ifthe motor is of light weight and therefore small size and designed tooperate properly on relatively low pressure. The plug 93 can be readilyreplaced by a different plug having a difierent diameter orifice 94.

Fluid admitted at the inlet 66 and passed through the orifice 94 flowsin a bore 95 aligned with the inlet to a port 96 in the valve sleeve 5!.The bore 95, as shown, is arranged to be obstructed by a rotary valveplug 91 in a valve sleeve 98 and which functions as a parking controlvalve as will be described later. Assuming that the valve plug 91 ispositioned, as in Fig. 3, so-as not to obstruct the bore 95, fluidpasses through 2,4 eases the port 96 to a lower recess 99in the valvecylinder and thence to a similarly disposed recess Illil at the upperside of the cylinder. An appropriate cross passage [ill in the valvecylinder connects the two recesses.

The lower recess 99 of the valve cylinder is always in opencommunication with the port 95. In the particular position of the valvecylinder 58 illustrated in Fig. 3. the upper recess I55 communicateswith a lateral port I 32 in the valve sleeve, there being another portH33 in said sleeve operatively opposite the port I82 and which, in saidparticular position of the valve cylinder, is closed to communicationwith the recess E90. When the valve cylinder 59 is turned clockwisethrough said angle of approximately 60 degrees the recess I69communicates with the port I63 but not with the port IEBZ. Appropriatechannels I64 and IE on the valve sleeve, formed for example as flatmilling cuts I95 and H (cf. Fig. 5), enables communication of the twoports i522 and I 03 with opposite bores in the housing II extendingtoward the axis of the valve cylinder. The channel Hi4 communicates witha diagonal bore Hi6 leading to the annular chamber 2i oi the motorcylinder space 3!, lying to the left of the piston 25. Thus, assumingthe valve cylinder is in the position shown in Fig. 3, fluid passes fromthe inlet to through the port recess 99, and cross passage Ilii to therecess 56th, thence through port I92, recess I84 and bore itl'c to themotorcylinder space 3i causing the motor piston to be driven to theright. Exhaust fluid from the motor cylinder space 32 at the right ofthe piston is simultaneously ejected through the valve cylinder 5|] tothe space 57 containing the snap action mechanism by thefollowingarrangement.

Directly opposite the entrance portion of the bore I86 a bore is formedas at it! parallel to the inlet bore 95 and crossing the bore in whichthe parking valve plug 97 is received. Assuming the parking valve is inthe position shown'on 3, the two ends of the bore IE! will becommunicated through a cross passage in the plug er of the parkingvalve. A diagonal bore IE8 communicates the right hand end of the boreill? with the annular space 22 which leads to the right hand'cylinderchamber 32 of the motor. The'left hand end of the bore it? interceptsthe channel I formed by the fiat cut I595 of the valve sleeve 5| so thatsaid'right hand motor cylinder space 32 is nowcommunicated with the portI??? of said valve sleeve. The valve cylinder 53 has on opposite sidesand leading from end to end of the uniform diameter portion of thecylinder, longitudinal channels lid and III. Those channels are inconstant communication with each other through cross passages I I2-seeparticularly Figs. 2 and 4. As will be clear from Fig. 2, the rear--ward ends of both channels no and iii are in open communication at alltimes with the generally rectangular space 57 of housing I! surroundingthe snap action toggle mechanism. That space, in turn, is in constantcommunication with the outlet passage 2% through a diagonal bore H5 asclearly shown on Fig. 6.

When the valve cylinder is turned as previously described to itsoperatively opposite position (rotated clockwise 60 degrees fromposition of Fig. 3) then'the recess Ito communicates only with the portI03, that is, it does not communicate with the port I02. Therefore, insaid other position of the valve cylinder, the pressure fluid isadmitted to the right hand motor cylinder space 32;

and, since the channel lI'I will then be aligned- 8 with the port. I62,the left'hand motor cylinder chamber 33 will becommunicated with theexhaust fluid outlet 9| in exactly the same manner as the chamber 32'was previously made to communicate with said outlet.

Comparison of Figs. 3 and 4 will make clear themanner in which bothinlet and exhaust fluid pressures are balanced about the center of thevalve cylinders so that in the stopped positions of the valve cylinder58 and while turning from one position to another there is no tendencyfor the cylinder to bind in its guiding sleeve. Such a function isparticularly valuable when, because of the small sizes of the unit, very1ittle power is made available to move the valve from stopped positionor, in other words, to overcome static friction. The channels Ilc or IIIare identical in Width and diametrically opposite each other wherefore,because the two channels are interconnected through the passages H2,both sides of the valve are subjected to the same outlet pressure at alltimes so long as one of the channels is in communication with dischargefluid as is the channel lit in relation to the piston chamber 32 in Fig.3. While the valve is moving from that position into a position in whichneither channel H9 or III communicates with a port of the valve sleevethe pressurein the two channels will nevertheless remain equalized.Similarly, since the flattening cuts on opposite sides of the valvecylinder forming. the chambers 99 and I fill are of the same area anddiametrically disposed with reference to the valve cylinder axis, inletpressure fluid is always balanced on opposite sides of the valvecyliinder through the cross connecting passage It Referring further tothe parking control mechanism (valve 97) for causing the shaft I2 tomove to a position of rest, the sleeve 93 is pressed into the verticalbore H5 formed in the lower port-ion of the housing I 5 and opening intothe cylinder bore of the housing which receives the cylinder sleeves.The plug or valve cylinder 5%? is rotatably received within the sleeve98 and a tapered lower end portion terminating in a cylindrical portionllesuitably knurled to facilitate manual adjustment. If desired, aflexible shaft (not shown) may be secured to the portion I it foroperating the parking control mechanism from a remote station.

The lowermost end of the bore H5 is counterbored and threaded to receivea sealing nut II? which, when threaded into position, forces a suitablepacking lli' against the end face of the sleeve 98 and against theperiphery of the cylinder S2. The packing I I 'l'bears on thecylindrical adjacent surface of the valve plug 9'! with sufilcient forceto prevent accidental dislocation of the plug.

The bore I it intersects both the passage 95 and passage I ti as alreadymentioned. Axial movement of valve cylinder 5? out of position is pre-"vented and the extent of rotary movement thereof is limited by a pin iis removably secured to the housing I! as by the threaded connection H9.The reduced inner end of the pin its projects through a lateral openingin the sleeve 98 into a slot liifl which extends for ninety degreesalong the circumference of the valve cylinder 91. The cylinder may thusbe rotated between two fixed turned positions disposed ninety degreesfrom each other.

A pair of diametrical bores I2l and l22 (Figs. 3 and'l, are formed inthe cylinder *9? in position to align with both'ipa'rts oi'each of theboresor passages linder is in one of its extreme turned positions (Fig.3) and are normal to those passages when the cylinder is in the other ofits extreme turned positions (Fig. 7). Displaced ninety degrees from thebores l2! and 22, Fig. 7, are a pair of diametrically opposedlongitudinal double-deadended slots I25 and IE of suflicientlongitudinal extent to connect the passages 95 and till.

When the valve cylinder 91 is in the turned position of Fig. 3 the motoroperates continually if supplied with fluid under sufiicient pressure.However, when the cylinder 91 is in the turned position of Fig. '7, theslot [24 causes high pressure fluid entering the motor at the port 9!!to flow from the passage 95 into the passage I01 and thence into thepiston chamber 32 where it forces the piston 25 to the left (Fig. 3).Assuming that the piston 25 is in its right hand position at the instantthe cylinder 91 is turned to the position of Fig. 7, fluid is dischargedfrom the piston chamber 3| in the manner already described until thevalve cylinder 59 is moved to its turned position, not illustrated,after which additional fluid is forced from the chamber 3! through thepassage I06, the port I02 and the valve chamber channels I I0 and I l Ito the chamber or space 51 of the housing and thence to the dischargeoutlet 9|. Since an exhaust path for all of the fluid in the pistonchamber 3| is provided, the piston 25 moves farther to the left thanduring normal operation and the shaft I2 is driven to a position of restbeyond its usual range of oscillation. 'So long as the valve 91 is inits turned position of Fig. '7, the p ston 25 is held in its extremeleft hand position by the static pressure of the fluid in the supplyline (not shown) leading to inlet port 99. If a windshield wiper bladewere be ng operated by the shaft I2. it may thereby be moved to a parkedposition beyond the usual range of vision and held in that position byfluid pressure. Returning the valve cylinder 91 to its initial position,Fig. 3, causes the motor to resume normal operation.

It will be apparent that speed control of the motor is also provided bythe park ng control mechanism just described. If the cylinder 91 isturned but slightly from its normal position of Fig. 3, the fluid pathsbetween the passages 95 and l 01 and the respective bores becomerestricted depending upon the extent of movement of the valve cylinder91. Since the speed of the motor is dependent upon the amount'of fluidsupplied thereto, it is thus possible by limiting the rate of fluid flowthrough the passage I25 to vary the motor speed from a maximum to a slowspeed near standstill regardless of the fixed volume-limiting effect ofthe orifice 94 of the plug 93. The valve 91, in other words, may be setto restrict the input of fluid to less than normally admitted for motoroperation by the orifice plug 93.

If it is desired to change or adjust the normal stroke of the pistonthat can be accomplished by substituting larger or smaller abutment pins80 and BI on the plate 15 of the motor piston. If a set of smaller pinsis used the effect will be to delay the operation of the snap actiontoggle mechanism in relation to the strokes of the piston, resulting inthe performance of longer strokes. Substitution of larger pins shortensthe strokes. By that means an infinite variation in stroke length ispossible.

I claim:

1. In a fluid operated motor of the type having 95 and I01,respectively, when the cya reciprocatable piston means, a rotatablevalve means for controlling the operation of the piston means, a snapaction toggle mechanism including spring-connected coaxially pivotedtoggle arms operatively interconnecting said valve means and. saidpiston for driving said valve means with alternate rotary motion uponreciprocation of said piston, one of the toggle arms acting againstcircumferentially spaced abutments on the rotary valve means to turn thelatter, said one toggle arm and the valve being brought respectively toarrested zero moment arm positions solely by mutual contact.

2. In a fluid operated motor of the type having a reciprocatable pistonmeans, a rotatable reversing valve member having circumferentiallyspaced abutments parallel to its axis, said valve member being arrangedfor controlling the operation of the piston means, a snap action togglemechanism including spring-connected coaxially pivoted toggle armsoperatively interconnecting said valve member and said piston fordriving said valve member with alternate rotary motion uponreciprocation of said piston, one of the toggle arms and the valve beingbrought respectively to arrested position at each reversing operation ofthe motor when the longitudinal center line of said arm is perpendicularto a line passing through the abutment and the center of rotation of thevalve member.

3. In a fluid operated motor, a reciprocatable piston, a rotaryreversibly acting valve arranged for controlling operating fluid inrespect to the piston, a snap action toggle mechanism driven by saidpiston and acting on the valve to turn it from one position to areversed position, said toggle mechanism comprising a pair of coaxiallypivoted double toggle arms, and a spring connecting the free ends ofsaid arms, one of the arms being arranged for operative engagement bysaid piston and the other for operative engagement with spaced abutmentson the rotary valve, said snap action toggle mechanism including arelatively rigid member straddling the spring and having coaxial fixedpivots for each of the arms at opposite sides of the plane of operationof the spring.

4. In a fluid operating motor, a housing, a reciprocatable piston in thehousing, a reversibly acting valve in the housing for controlling asupply of operating fluid for the piston, a snap action toggle mechanismdriven by said piston and acting on the valve to move it from one fluidsupplying position to a reversed fluid supplying position, said togglemechanism comprising a pair of spring connected double toggle arms, onearranged for operative engagement by said piston and the other arrangedfor operative engagement with spaced abutments on the valve, said snapaction mechanism including a rigid member having axially aligned andspaced apart pin portions pivotally supporting each of the arms atrespective pin portions of said rigid member, and a rigid supportremovably secured to the housing and forming, with said rigid member andthe toggle arms, a self-sustaining assembly unit separable from theremainder of the motor.

5. In a fluid operated motor of the class described, a housing, areciprocatable piston in the housing, a reversibly acting valve in thehousing for controlling the flow of pressure fluid alternately toopposite ends of the piston, a rigid bracket removably secured to saidhousing in.

spaced relation to the piston and valve, a snap action toggle mechanismincluding a hollow yoke member carried on and removable with saidbracket and having axially spaced pivot pin portions, double toggle armseach pivotally supported on both pivot pin portions of the yoke member,and a spring connecting the free ends of the arms and passing throughthe hollow portion of the yoke member whereby to eliminate cantileverforces applicable to the toggle arms by such spring.

'6. A fluid operated motor comprising a body formed with opposed pistonchambers and a valve chamber, reciprocatable piston means in the pistonchambers, said body being formed with a fluid supply. and a fluiddischarge passage and passages extending between said chambers, a valvemembersupported in said valve chamber and operable to control the flowof fluid between said fluid supplying passage and said passageextending'between said chambers, a valve actuator mechanism constitutinga driving connection between said piston means and said valve member foractuating said valve member automatically, and a second valve memberarranged for directly interconnecting said fluid supply passage and oneof said passages extending between said piston chambers, said secondvalve member including means for completing an exhaust fluid passage inloop arrangement with respect to said valve chamber simultaneously withinterconnecting the aforesaid passages.

7. A fluid operated motor comprising a body formed with a bore providinga pair of opposed cylinders and a further bore providing a valvechamber, said body being formed with a fluid supply and a fluiddischarge passage and passages extending between said bores, pistonsmounted for reciprocation within said cylinders andrconnected to move insynchronism, a first plug type valve member rotatably supported in saidchamber and operable upon rotation to control the flow of fluid betweensaid fluid supplying passages and said passages extending between saidbores, a valve actuator constituting a driving connection between saidpistons and said first valve member for actuating said valve memberautomatically, and a second rotary plug type valve. member for directlyinterconnecting said fluid supply passage and one of said passagesextending between said bores, said second rotary valve member includingmeans for completing a 'fluidexhaust passage in loop arrangement withrespect to said valve chamber.

ating to supply and exhaust fluid alternately to and from the chambersthrough first and second branch passages connecting the respectivechambers and reversing valve, said first branch passage being alsocontrolled by the master valve, one of the control positions of themaster Valve establishing a direct connection between part of the supplyduct ahead of the master valve in the direction of fluid supply and saidfirst branch passage to cause a non-reciprocating movement or arrest ofthe power means and simultaneously establishing a connection between thepart of the supply duct lying beyond the master valve in said directionwith said first branch passage between the master valve and thereversing valve whereby the second branch passage can exhaust fluidthrough the reversing valve irrespective of the instantaneousposition ofthe latter.

9. In a fluid operated motor, a housing, a reciprocatablc piston in thehousing, a reversibly acting valve in the housing for controlling asupply or operating fluid for the piston, a snap action toggle mechanismdriven by said piston and acting on the valve to move it from one fluidsupplying position to a reversed fluid supplying position, said togglemechanism comprising two toggle arms each'iormed of a pair of spacedinterconnected generally parallel side elements, means pivotallyconnecting elements of each arm in overlapping relationship at a commonpivot axis, and a spring connecting the two arms at points lyingremotely of the pivot axis, said spring being movable between the spacedelements and across the pivot axis, said means including a mountingbracket on which the arms, spring and pivot means are carried as acomplete Working assembly, said bracket being removab ly attached to thehousing. s

COLUMBUS R. SACCHINI.

REFERENCES CITED UNITED STATES PATENTS Number. Name Date 456,837 OldsJuly 28,1891 660,010 Ezell Oct.16, 1900 746,955 Goodwin Dec. 15, 19031,012,164 Rose", Dec. 19, 1911 1,395,604 Skinner Nov. 1, 1921 1,424,890Folberth Aug. 8, 1922 1,487,405 Skinner Mar. 18, 1924 1,567,328 OisheiDec. 29, 1925 1,639,043 Malouf Aug. 16, 1927 1,663,666 Moskovitz et al.Mar. 27, 1928 FOREIGN PATENTS Number Country Date 473,296 Great BritainOct. 11, 1937 110,074 Germany Apr. 19, 1900 553,877 Germany July 1, 1932

